Simulations of Transonic Diffuser-Volute System Using Hybrid Unstructured CFD

2000 ◽  
Author(s):  
A. Hosangadi ◽  
V. Ahuja ◽  
Y. T. Lee
Keyword(s):  
Transonic Flow ◽  
Numerical Stability ◽  
Efficient Solution ◽  
Solution Procedure ◽  
Flow Conditions ◽  
Vaneless Diffuser ◽  
Parallel Solution ◽  
Water Region ◽  
Good Comparison ◽  
Comparison With Experimental Data

Abstract Simulations for a vaneless diffuser-volute configuration at transonic flow conditions are presented using a multi-element unstructured CFD code CRUNCH. The unstructured framework permits the generation of a contiguous grid without internal boundaries between the diffuser-volute interface, and also provides good local resolution around the cut-water region. The increased numerical stability resulting from these factors coupled with the parallel solution framework yields an efficient solution procedure. Numerical results indicate good comparison with experimental data for the baseline geometry where the measured performance was below the design prediction.

Multi-Element Unstructured Methodology for Turbomachinery Applications

2001 ◽  
Author(s):  
V. Ahuja ◽  
S. Arunajatesan ◽  
A. Hosangadi
Keyword(s):  
Numerical Stability ◽  
Efficient Solution ◽  
Flow Regimes ◽  
Solution Procedure ◽  
Numerical Results ◽  
Flow Physics ◽  
Parallel Solution ◽  
Rotor Stator Interaction

Abstract Simulations for turbomachinery applications in various flow regimes are presented using a multi-element unstructured CFD code CRUNCH. The unstructured framework permits the generation of a contiguous grid without internal boundaries between different components of a turbomachinery system, and provides good local resolution in regions where the flow physics becomes important. The increased numerical stability resulting from these factors coupled with the parallel solution framework yields an efficient solution procedure for complex turbomachinery flows. Numerical results are presented for a transonic diffuser-volute configuration and rotor stator interaction.

scholarly journals Axial-flow compressor analysis under distorted phenomena at transonic flow conditions

2018 ◽  
Vol 5 (1) ◽  
pp. 1526458
Author(s):  
G Srinivas ◽  
K Raghunandana ◽  
Shenoy B Satish ◽  
Duc Pham
Keyword(s):  
Transonic Flow ◽  
Axial Flow ◽  
Flow Conditions ◽  
Axial Flow Compressor ◽  
Flow Compressor

Refined Softened Truss Model with Efficient Solution Procedure for Prestressed Concrete Membranes

2018 ◽  
Vol 144 (6) ◽  
pp. 04018045 ◽  
Author(s):  
L. F. A. Bernardo ◽  
A. R. B. Lyrio ◽  
J. R. B. Silva ◽  
B. Horowitz
Keyword(s):  
Prestressed Concrete ◽  
Efficient Solution ◽  
Solution Procedure ◽  
Truss Model

Unsteady Modeling of Turbochargers for Automotive Applications by Means of a Quasi-3D Approach

2020 ◽  
Author(s):  
Gianluca Montenegro ◽  
Matteo Tamborski ◽  
Augusto Della Torre ◽  
Angelo Onorati ◽  
Silvia Marelli
Keyword(s):  
Test Bench ◽  
Tangential Direction ◽  
Momentum Equation ◽  
Conservation Equation ◽  
Design Flow ◽  
Automotive Applications ◽  
Flow Conditions ◽  
Vaneless Diffuser ◽  
Energy Conservation Equation ◽  
The University

Abstract This work describes the development and the application of a quasi-3D method for the simulation of turbochargers for automotive applications under unsteady flow conditions. The quasi-3D approach is based on the solution of conservation equations for mass, momentum and energy for unsteady flows and applied to 0D and 1D elements arbitrarily oriented in the space. The compressor is divided into different regions, each one treated numerically in a different way. For the impeller region a relative reference system has been used and the presence of a centrifugal force field has been introduced both in the momentum and energy conservation equation. The direction of the ports at the inlet and outlet of the impeller are used to determine the design flow angles and therefore the deviation during off-design conditions. Conversely in the vaneless diffuser the conservation of the angular momentum of the flow stream has been imposed in the tangential direction and then combined with the solution of the momentum equation in the radial direction. The model has been validated against measurements carried out on the test bench of the University of Genoa both in diabatic and adiabatic conditions.

scholarly journals Non-conserving Flow Aspect of Maximum Dynamic Flow Problem

2018 ◽  
Vol 14 (1) ◽  
pp. 107-114
Author(s):  
Phanindra Prasad Bhandari ◽  
Shree Ram Khadka
Keyword(s):  
Network Flow ◽  
Efficient Solution ◽  
Flow Problem ◽  
Dynamic Network ◽  
Maximum Flow ◽  
Solution Procedure ◽  
Evacuation Planning ◽  
Planning Problem ◽  
Intermediate Node ◽  
Flow Conservation

Shifting as many people as possible from disastrous area to safer area in a minimum time period in an efficient way is an evacuation planning problem (EPP). Modeling the evacuation scenarios reflecting the real world characteristics and investigation of an efficient solution to them have become a crucial due to rapidly increasing number of natural as well as human created disasters. EPPs modeled on network have been extensively studied and the various efficient solution procedures have been established where the flow function satisfies the flow conservation at each intermediate node. Besides this, the network flow problem in which flow may not be conserved at nodes necessarily could also be useful to model the evacuation planning problem. This paper proposes an efficient solution procedure for maximum flow evacuation planning problem of later kind on a single-source-single-sink dynamic network with integral arc capacities with holding capability of flow (evacuees) in the temporary shelter at intermediate nodes. Journal of the Institute of Engineering, 2018, 14(1): 107-114

A Study of Induced Vorticity in Centrifugal Compressors

1964 ◽  
Vol 86 (1) ◽  
pp. 63-73 ◽  
Author(s):  
G. O. Ellis
Keyword(s):  
Flow Rate ◽  
Energy Exchange ◽  
Mathematical Treatment ◽  
Rotational Flow ◽  
Flow Conditions ◽  
Vaneless Diffuser ◽  
Real Fluid ◽  
Flow Part ◽  
Apparent Shift ◽  
Viscous Stresses

Recent investigations have moved a step closer to an understanding of real fluid phenomena in turbomachines by studying rotational flow once it has been established by viscous stresses and nonuniform exchange of energy. The present paper presents a more generalized mathematical treatment of rotational flow (Part I) and makes use of the equations developed to analyze experimentally observed phenomena in the impeller (Part II) and the diffuser (Part III) of a compressor. These studies show that induced vorticity in the impeller produces a nonuniform energy exchange which is the basis for additional rotational effects in the diffuser. Also the amount of vorticity generated varies with flow rate which increases the sensitivity of downstream components to changes in flow rate and thereby reduces compressor range. In the particular diffuser studied, the flow conditions, up to the point of separation, were all established primarily by the induced vorticity while shearing stresses next to the wall seemed to have a negligible influence. Downstream from the beginning of separation, however, an apparent shift in energy distribution is observed which could not be accounted for by the analysis. It is demonstrated that separation is detrimental to vaneless diffuser performance only if it is located at the diffuser discharge. Since the location of separation is a function of the vorticity induced, which varies with the flow rate, a widely spaced diffuser can have substantial variations in performance with a significant influence on the compressor characteristics.

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